Marine vehicles can be categorized as either static-lift (displacement) craft or dynamic-lift craft. Static-lift craft tend to be more stable than dynamic-lift craft, but slower than them.
For a static-lift craft, buoyant force is generated by the displacement of a portion of the supporting medium, which is water for the case of a marine vessel. Dynamic-lift craft derive their lift from the movement of a foil (e.g., wing, etc.) through air, water, or both.
Static lift is more economical than dynamic lift from a production-of-lift point of view. But a static-lift craft becomes relatively inefficient when it is required to move through the surrounding medium (water). Due to the nature of displacement buoyancy, static-lift craft develop a substantial amount of dynamic drag when in motion. Examples of static-lift craft include mono-hull ships, catamarans, and SWATH (small waterplane area twin hull) craft.
Dynamic-lift vessels are typically faster than static-lift craft because they develop less dynamic drag. A principle shortcoming of the dynamic-lift craft is that it requires forward motion of some finite velocity to generate lift. As a result, this type of craft cannot operate, as such, at relatively slower speeds. Examples of dynamic-lift craft include hydrofoil ships, WIG (wing-in-ground) effect craft, seaplanes, and ACV (air cushion vehicles).